A communication technology for transmitting wireless signals to a same mobile station apparatus by coordination of a plurality of cells so as to improve the quality of communication has been known. One example of such a communication technology is “coordinated multi-point transmission (CoMP)” which is studied in the LTE (Long Term Evolution)-Advanced for which standards are in the process of being formulated by the 3GPP (3rd Generation Partnership Project).
As related art, a mobile terminal cluster-based coordinated communication system (for example, see Japanese National Publication of International Patent Publication No. 2012-510771) is known. This coordinated communication method includes a stage of receiving an allocation of a resource of a weighted sub-band which is mapped on a coordinated base station cluster, one type of the coordinated base station clusters which are set in advance, which has a group including a serving base station of a mobile terminal and base stations giving dominating interference to the mobile terminal which are found by channel estimation and a stage of communicating with the serving base station in coordination with the base stations giving dominating interference to the mobile terminal.
Further, there is known the art of switching the type of coordination in coordinated multi-sector communication (for example, see Japanese National Publication of International Patent Publication No. 2012-507216). The base station equipment which governs a sector determines one or more coordinating sectors of a mobile terminal and, in accordance with rules defined in advance, uses the information of the one or more coordinating sectors as the basis to determine the type of coordinate multi-sector communication which is provided in coordination with the one or more coordinating sectors and provides coordinated multi-sector communication of the corresponding determined type to the mobile terminal in coordination with the one or more coordinating sectors.
Further, there is known a mobile terminal apparatus which receives downlink signals which include reference signals from a plurality of wireless base station apparatuses relating to downlink CoMP and transmits feedback information which includes results of measurement of channel quality to the plurality of wireless base station apparatuses (for example, see Japanese Laid-Open Patent Publication No. 2012-510771, No. 2012-507216). The wireless base station apparatuses receive uplink signals which include the results of measurement of channel qualities of the plurality of wireless base stations relating to downlink CoMP and cell information relating to wireless base station apparatuses with average reception levels within a first threshold range and when there are wireless base station apparatuses with differences from the average reception level within a second threshold range among the wireless base station apparatuses with average reception levels within the first threshold range, control the transmission powers to the two groups of wireless base station apparatuses.